| Message ID | 20200127035318.qjbykxzoqgzsgsvl@debian |
|---|---|
| State | New |
| Headers | show |
| Series | [FFmpeg-devel] avfilter/pad: round output width/height up instead of down. Fixes bugs #1618 and #8475. | expand |
| Context | Check | Description |
|---|---|---|
| andriy/ffmpeg-patchwork | success | Make fate finished |
Hoping someone can review this and apply it if it looks good. > The pad filter is currently broken for cases where all of the following hold: > > (1) chroma subsampling exists (very common), > > (2) an input dimension is odd (uncommon), and > > (3) the corresponding output dimension is either the same as the input, > or an expression like "ow-iw" or "oh-ih" is used to place the image at > the right/bottom edge and the extra padding is even in size. > > The cause of the breakage is essentially that the output width and > height are being rounded downward, causing the image to exceed the > padded area slightly. > > It seems best to me to simply round the output width/height up instead > of down, so I've attached a patch to do that. This fixes bugs #1618 and > #8475. > > Commands to reproduce the bug: > > # create 15x15 test jpeg with 4:2:0 subsampling > ffmpeg -f lavfi -i color=red:15x15,format=rgb24 -vframes 1 -vf format=yuvj420p red.jpg > > # output size = input size. fails > ffmpeg -i red.jpg -vf pad=iw:ih:0:0 pad1.png > > # input at bottom right of output. fails > ffmpeg -i red.jpg -vf pad=iw+16:ih+16:ow-iw:oh-ih pad2.png > > Ivan > > --- > libavfilter/vf_pad.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/libavfilter/vf_pad.c b/libavfilter/vf_pad.c > index e86292e..493e342 100644 > --- a/libavfilter/vf_pad.c > +++ b/libavfilter/vf_pad.c > @@ -178,8 +178,8 @@ static int config_input(AVFilterLink *inlink) > if (s->y < 0 || s->y + inlink->h > s->h) > s->y = var_values[VAR_Y] = (s->h - inlink->h) / 2; > > - s->w = ff_draw_round_to_sub(&s->draw, 0, -1, s->w); > - s->h = ff_draw_round_to_sub(&s->draw, 1, -1, s->h); > + s->w = ff_draw_round_to_sub(&s->draw, 0, +1, s->w); > + s->h = ff_draw_round_to_sub(&s->draw, 1, +1, s->h); > /* sanity check params */ > if (s->w < inlink->w || s->h < inlink->h) { > av_log(ctx, AV_LOG_ERROR, "Padded dimensions cannot be smaller than input dimensions.\n"); > -- > 2.20.1
From 52030219e09b5f9611ca6232b1f24197363fc23b Mon Sep 17 00:00:00 2001 From: Ivan Middleton <ivan.middleton@gmail.com> Date: Sun, 26 Jan 2020 20:25:59 -0700 Subject: [PATCH] avfilter/pad: round output width/height up instead of down. Fixes bugs #1618 and #8475. --- libavfilter/vf_pad.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libavfilter/vf_pad.c b/libavfilter/vf_pad.c index e86292e..493e342 100644 --- a/libavfilter/vf_pad.c +++ b/libavfilter/vf_pad.c @@ -178,8 +178,8 @@ static int config_input(AVFilterLink *inlink) if (s->y < 0 || s->y + inlink->h > s->h) s->y = var_values[VAR_Y] = (s->h - inlink->h) / 2; - s->w = ff_draw_round_to_sub(&s->draw, 0, -1, s->w); - s->h = ff_draw_round_to_sub(&s->draw, 1, -1, s->h); + s->w = ff_draw_round_to_sub(&s->draw, 0, +1, s->w); + s->h = ff_draw_round_to_sub(&s->draw, 1, +1, s->h); /* sanity check params */ if (s->w < inlink->w || s->h < inlink->h) { av_log(ctx, AV_LOG_ERROR, "Padded dimensions cannot be smaller than input dimensions.\n"); -- 2.20.1